A compact refractometer with an ultra pure modified PTFE flow cell body for semiconductor liquid chemical processes. Connected to the process by a ¼ — 1 inch pillar or flare fitting.

Vaisala K-PATENTS® Semicon Refractometer PR-33-S monitors the fab chemicals' concentration in cleanroom environment and in the integrated process tools (blending, clean, etch, and CMP).

The PR-33-S consists of an ultra-pure, modified PTFE flow cell body and an Ethernet cable that any standard PoE (Power-over-Ethernet) switch can use to transmit power to the sensor and data to a computer. The PR-33-S monitors chemical concentrations in real-time and provides an Ethernet output signal and immediate feedback, if the chemical is out of specifications. For example, low and high concentration alarms may be configured to control and increase bath life. The concentration is determined by making an optical measurement of the solution’s Refractive Index nD and temperature.

The PR-33-S is mounted directly in-line with a flare or pillar fitting. The PR-33-S has a compact, metal-free construction and it only needs a small footprint area.

Key Features:

  • PR-33-S is used for process control and monitoring.
  • Compact and mounted directly in-line. The measurement is not influenced by particles, bubbles or turbulent flow and impurities in the ppm range.
  • Provides a continuous Ethernet output signal; 4-20 mA outputs available as option.
  • Full measurement range Refractive Index nD 1.3200–1.5300, which corresponds to 0-100 % by weight. Optional range nD 1.2600–1.4700 for strong HF.
  • Typical accuracy R.I.+ 0.0002, which typically corresponds to 0.1% by weight, e.g. for HCl in water.
  • N.I.S.T. traceable calibration, verification with standard R.I. liquids and K-Patents documented procedure (ISO 9000).
  • Patented CORE-optics (US Patent No. US6067151): no drift, no re-calibration, no mechanical adjustments.
  • Remote panel via Ethernet for data-logging and remote operation.
  • The communication is built by the standard UDP/IP protocols.
  • Process temperature range: -20°C – 85°C (-4°F – 185°F).
  • Fast process temperature measurement by built-in Pt1000 and automatic digital temperature compensation.